577

1 INTRODUCTION

The Automatic Identification System (AIS) has been

discussed in a number of studies as it represents an

aid that significantly contributes to the safety of

navigation [6, 9, 10, 13–15]. Some of these studies

focus on the errors that occur when using the AIS

system [2, 3, 7, 8]. The users of on-board AIS devices

should be familiarised with the proper use of the

equipment and the errors that may be made when

using it. The problem of insufficient AIS

familiarisation may also arise from the failure of

updating the data that the system processes. This

leads to a hypothesis on the insufficient training of

seafarers and their familiarisation with the AIS

devices and their errors. This research is aimed at

increasing the safety of navigation in the Adriatic and

other seas, and thereby, better accident prevention

and protection of human life and material property at

sea. The research involved a survey carried out on

various vessels operated by Jadrolinija shipping

company and in coast stations, including a number of

seafarers and shore-based staff over a period of one

month. The questionnaires were delivered to the crew

members trained for using AIS devices. The results

produced by the survey are presented in tables and

diagrams. They have been evaluated and compared to

the expected outcomes through the comparative

analysis. The results produced by the survey will be

used for creating a model for improving the use of the

AIS system.

2 ERRORS IN USING THE AIS EQUIPMENT

The errors occurring in using the Automatic

Identification System (AIS) equipment can be divided

Research Study and the Model for Improving the Safety

of Navigation when Using the AIS

D. Medić

, M. Bukljaš

, R. Bošnjak

& S. Vukša

University of Split, Split, Croatia

University of Zagreb, Zagreb, Croatia

ABSTRACT: The use of the Automatic Identification System (AIS) devices for ensuring the safety of navigation

and the errors occurring when using AIS equipment have been the focus of a number of research studies. The

users of AIS equipment installed onboard sea-going vessels are required to familiar with the proper use of the

devices and potential errors that may occur. A significant problem revealed in this study is the lack of

understanding of potential error sources and the necessity to eliminate such errors prior to transmission of the

AIS data message reading of the errors and failure to update the data processed by the AIS system. This results

in a hypothesis on the insufficient training of seafarers and their familiarisation with the AIS devices and errors.

This research is aimed at increasing the safety of navigation in the Adriatic Sea, as well as other seas, i.e. better

accident prevention and protection of human life and material property at sea. The results produced by the

research are used as an input for creating a model for enhancing the safety of navigation when using the AIS,

through additional training of the seafarers.

http://www.transnav.eu

the International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 15

Number 3

September 2021

DOI: 10.12716/1001.15.03.10

578

into two categories: technical and human errors [3].

Technical errors refer to the loss of signal, offset of the

ship’s position, incompliance of the targets displayed

on AIS, ECDIS or radar. Due to these drawbacks, the

AIS receiver is not allowed to be used as the principal

aid to navigation. Human errors mainly refer to the

inappropriate use of the devices, e.g. failing to enter

important data about the status of the vessel (whether

it is under way, moored or at anchor), or failing to

enter the updates on dangerous cargo, estimated time

of arrival (ETA) or estimated time of departure (ETD).

The system and errors can be shown through the

model in Figure 1.

Figure 1. General model of errors in the AIS system [3]

3 METHODOLOGY OF COLLECTING

INFORMATION

This research uses the survey in the form of

questionnaires, which is a common tool in numerous

studies [1, 4, 5, 11, 12]. The questionnaires provide

information, opinions and views on the issue.

Compared to other tools of collecting information

(observation, interviews, assessment, testing and

analysis of technical documentation), the survey has

the following advantages:

− provides insights into the experience,

− provides information on the past, present and

future, and

− represents an economical tool.

3.1 Comparative analysis of information

A comparative analysis of the responses obtained

through the questionnaires has been performed. The

following responses have been analysed:

− how many types of AIS devices are the seafarers

familiar with, with regard to their rank and age,

and

− familiarisation with the AIS equipment errors,

with regard to their rank and age.

The first question provided an insight into the

types of AIS devices that the seafarers are familiar

with. The accuracy of the responses were analysed,

with reference to the rank of the seafarer. The second

question provided an insight into the familiarisation

of seafarers with the errors in the AIS devices. The

accuracy of the responses were analysed, with

reference to the rank of the seafarer. The comparative

analysis has been used to present the obtained results

in tables (Tables 1 – 3).

Table 1. Total number of respondents and their rank and

age distribution

_______________________________________________

Respondents and their age 20-40 40-55 55 and older

_______________________________________________

Master 4 11 4

Mate 5 4 1

Officer in charge of 7 2 0

a navigational watch

_______________________________________________

Table 2. Number of correct responses for types of AIS

devices by the age and rank

_______________________________________________

Respondents and their age 20-40 40-55 55 and older

_______________________________________________

Master 2 10 1

1st Mate 4 3 0

Officer in charge of 4 1 0

a navigational watch

_______________________________________________

Table 3. Number of correct responses for familiarisation

with AIS errors by the age and rank

_______________________________________________

Respondents and their age 20-40 40-55 55 and older

_______________________________________________

Master 2 5 0

1st Mate 3 2 0

Officer in charge of 1 1 0

a navigational watch

_______________________________________________

3.2 Selection of the gathered data

The selection of the gathered information is

considered an important part of the research work.

All relevant data must be systematically categorised,

with regard to their quality. The information that is

irrelevant for the study has to be excluded. Without a

quality selection, the gathered data cannot produce

results that are relevant and useful for the research.

The selection of the gathered data can be, in this case,

observed through three stages:

− data processing,

− establishing the validity, and

− interpretation of the validity (bringing into

relationship with the ideas that drive the research).

The survey involved 38 respondents and was

aimed at establishing the level of their competency in

using the Automatic Identification System (AIS)

devices. Based on the research results, the goal was to

establish the elements that are essential for shaping a

standardised training course in using AIS equipment

and to analyse the discrepancies of the produced

results. The surveyed population mainly consisted of

the masters (50% respondents) and senior and junior

deck officers serving on board vessels of Jadrolinija

shipping company (the remaining 50% respondents).

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Graph 1. Number of seafaring respondents by rank

After the survey was performed on vessels of

various size and fitted with various equipment, the

data gathered by questionnaires were subjected to the

selection procedure. The questions referred to (Annex

1):

− age of respondents,

− qualification,

− rank on board,

− number of types of AIS devices the respondent is

familiar with,

− familiarisation with AIS device functioning,

− familiarisation with the AIS system errors,

− incidence of testing AIS devices,

− timely updating information on the voyage,

− incidence of failing to update information,

− detecting the insufficiency of data from other

vessels (speed, distance from the ship, course,

position, and the like),

− use of the AIS as an aid to navigation, aimed at

preventing collision at sea, along with other aids to

navigation,

− information about stations for testing AIS devices,

− recognising the AIS acronym.

The selection of the gathered information was

performed with regard to the AIS acronym for the

purpose of recognising and interpreting the basic AIS

features.

The data were selected with reference to the age,

education and rank of the respondents. This form of

selection was necessary as it is assumed that younger

and better trained crew members provide accurate

answers to a relatively larger extent.

On the other hand, the survey results are expected

to be poorer than the results that might be gathered on

the deep-sea vessels. Namely, the officers engaged on

international voyages use the AIS system more often

than the officers engaged in domestic trade, for the

purpose of observing other vessels, and their

familiarisation with the AIS system is more often

controlled by the Port State Controls (PSC) and other

authorised entities, such as the United States Coast

Guard (USCG).

3.3 Validation of data

It was suggested that, after the selection of the above-

mentioned information, the validation of the

information was carried out. The validation took into

consideration the data that were essential in the

operation of the Automatic Identification System

(AIS) devices and in showing to what degree the crew

members in charge of using the AIS were trained for

using the available equipment.

The validation was carried out through checking

the familiarisation with the AIS equipment and with

implementing the basic procedures (five basic

procedures) when using the AIS:

− testing the AIS devices with shore-based stations,

− testing the AIS devices with nearby vessels,

− entering necessary parameters before and during

putting out to sea,

− recognising the errors of the very device, and

− level of knowledge in using the very device.

3.4 Presentation of the processed data

During the survey, each question obtained various

responses. They are presented in the graphs below.

The responses refer to the vital part of the survey,

which can be viewed from the standpoint of the safety

of navigation, i.e. the set of rules and regulations

ensuring a safe navigation. The following function of

the safety of maritime navigation when using AIS

equipment is suggested:

( ) ( )

, ,,f S TWED=

(1)

The above function can serve as a base for

suggesting a technically acceptable definition of the

safety of navigation (S) as a process consisting of the

following elements: T – familiarisation with the AIS

devices, W – operation of AIS devices, E – errors of

AIS devices, and D – drawbacks of AIS equipment.

Graph 2. Familiarisation with the types of AIS devices (T)

Graph 3. Familiarisation with the operation of AIS

equipment (R)

580

Graph 4. Familiarisation with errors in AIS equipment (E)

Graph 5. Recognising the drawbacks of the AIS equipment

(D)

The above graphs, and the processed data they

show, refer to the relevant parts of the survey,

including:

− familiarisation with the types of AIS devices,

− familiarisation with the operation of AIS devices,

− familiarisation with the errors of AIS devices, and

− familiarisation with the drawbacks of AIS

equipment.

4 MODEL FOR IMPROVING THE SAFETY OF

NAVIGATION WHEN USING THE AIS

In the comparative analysis of two questions, Table 3

shows a relatively high rate of incorrect answers

compared to Table 2. This results in concluding that

the issue of familiarisation with the types of errors in

the AIS system is far more complex and less familiar

than the issue of familiarisation with the types of the

AIS devices. Considering the results produced by the

comparative analysis, it can be concluded that it is

necessary to introduce additional measures in terms

of seafarers’ training, in order to familiarise them

better with the AIS errors and, consequently, bring the

safety of navigation to a higher level. A thorough

analysis of error types and their definition by risk

degree is suggested. A model for improving the

training of seafarers aimed at raising the safety of

navigation level is suggested (Figure 2). The new and

enhanced model represents an upgrade of the

previously developed training models [3].

The above presented model indicates that the AIS

standard comprises two classes:

− Class A, and

− Class B.

VESSEL > 300 GT

CARRYING > 12

PASSENGERS?

INTRODUCTION

OF ADDITIONAL

TRAINING FOR

AIS EQUIPMENT

CLASS B AND ITS

ERRORS AND

DRAWBAC KS

WITH REGARD TO

CLASS A

INTRODUCTION

OF ADDITIONAL

TRAINING FOR

AIS EQUIPMENT

CLASS A AND ITS

ERRORS

END

AIS EQUIPMENT

CLASS B

VESSEL > 500 GT?

AIS EQUIPMENT

CLASS A

YES

START

SELECTION OF

VESSEL

VESSEL ON THE

INTERNATIONAL

VOYAGE?

FISHING VESSEL

VESSEL IN

COASTAL

NAVIGATION

OCEAN-GOING

VESSEL

AIS EQUIPMENT

CLASS A

YES

AIS EQUIPMENT

CLASS B

YES

INTRODUCTION

OF ADDITIONAL

TRAINING FOR

AIS EQUIPMENT

CLASS A AND ITS

ERRORS

INTRODUCTION

OF ADDITIONAL

TRAINING FOR

AIS EQUIPMENT

CLASS B AND ITS

ERRORS AND

DRAWBAC KS

WITH REGARD TO

CLASS A

YES

PROPOSAL OF GENERAL

COURSE IN USING AIS

EQUIPMENT

Figure 2. General model for improving the seafarers’ training and familiarisation with AIS equipment

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Class A is mandated for all vessels of 300 GT and

above engaged on international voyages, cargo vessels

of 500 GT and above not engaged on international

voyages, as well as for all passenger vessels (carrying

more than 12 passengers) regardless of their size. It is

estimated that, these days, around 40,000 vessels use

Class A equipment, while Class B has been in place

since 2007. Class B allows a new generation of AIS

devices that are more affordable, but have a limited

range and features. Class B equipment is typically

installed on smaller vessels such as fishing and

recreational boats. The survey results and the

empirical experience suggest that a large number of

seafarers do not use AIS equipment to the full, with

all the available features and possibilities.

Furthermore, the model involves fishing vessels (most

of them use Class B devices, while large ocean-going

fishing vessels may also carry Class A equipment).

Speaking empirically, fishing vessels do not update

the system and it often occurs that a fishing vessel

appears on the screen as a target that does not move,

the so-called sleeping target. Another problem is the

inability of such vessels to timely detect large

merchant ships as targets, especially in poor visibility.

Therefore, the additional training is suggested as

presented in the model (Figure 2).

5 CONCLUSION

The Automatic Identification System (AIS) equipment

in coastal navigation is still in the stage of

development and implementation. Some of the vessels

still fail to use the AIS features to the full, mainly due

to insufficient training of the crew. This was one of the

essential reasons for conducting a survey on the use of

the AIS system and the familiarisation with AIS

devices and their drawbacks among the ship masters

and mates on the Jadrolinija company vessels. The

results of the questionnaires indicate that most of the

officers in charge have elementary knowledge that

allows them to use basic features of the AIS

equipment. However, somewhat harder questions

provide a more detailed into the training and

familiarisation, which are insufficient. Therefore, a

general model for improving the safety of navigation

when using the AIS is suggested, involving additional

training of seafarers. It will be possible to further

update and adjust the model, depending on the future

research and the results produced.

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Supplement

QUESTIONNAIRE (Annex 1)

This survey is anonymous and is designed to study the use

of AIS devices in coastal navigation

Place_____________

Date____________________

Note: circle only one answer

1. Age

a) from 20 to 40

b) 40 to 55

c) 55 and older

2. Education

a) high school

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b) undergraduate study (2-year, 3-

year or 4-year)

3. Rank on board (deck department):

a) master

b) 1st mate

c) Officer in charge of a navigational watch

4. How many types of AIS devices do you know?

a) 1

b) 2

c) 3

d) I don’t know

5. Are you familiar with the AIS equipment?

a) I am not familiar with the equipment

b) I use the equipment partially

c) I am familiar with the equipment very well

6. Are you familiar with the drawbacks / errors of the

equipment?

a) yes

b) no

c) partially

7. How often do you test the device?

a) Once a week

b) Once a day

c) Once a month

d) I don’t test the device

e) When I can

8. Does it happen that you don’t manage to timely update

the device when sailing?

YES NO

9. If the response to Q8 is yes, how often does it happen?

a) On almost every voyage

b) Once a day

c) Once in 3 days

d) Rarely

10. Do you notice that the information you receive from

other vessels is insufficient (e.g. missing course, speed,

position and the like)

YES NO

11. Do you use the AIS as an additional aid to navigation,

along with other sources (e.g. for detecting speed of

another vessel, distance from other vessels, their

courses, etc.)

YES NO

12. State the stations you can test the device with.

13. What does AIS stand for?